Pivot Shaft End Plate question

RCinNC

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I just got done with my most recent swingarm service. Part of the service involves removing the pivot shaft end plate. This is what it looks like:



If you look in the service manual about the swingarm removal procedure, it specifically makes note to remove this plate before you loosen the pivot shaft. Many miles ago when I did my first swingarm service, I stripped out the head of the lower socket head screw while trying to remove it, and absent removing the u-joint for more working room to extract the screw, I doubt it's ever coming out. So I continued the procedure with the pivot shaft end plate in place, and didn't have any issues.

Yesteday I did another swingarm service, and of course the same issue arose, with the same solution: I removed the pivot shaft with the end plate in place. I'm just really curious if someone here knows why Yamaha says to remove that plate when it doesn't seem necessary to do so.
 

holligl

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I just got done with my most recent swingarm service. Part of the service involves removing the pivot shaft end plate. This is what it looks like:



If you look in the service manual about the swingarm removal procedure, it specifically makes note to remove this plate before you loosen the pivot shaft. Many miles ago when I did my first swingarm service, I stripped out the head of the lower socket head screw while trying to remove it, and absent removing the u-joint for more working room to extract the screw, I doubt it's ever coming out. So I continued the procedure with the pivot shaft end plate in place, and didn't have any issues.

Yesteday I did another swingarm service, and of course the same issue arose, with the same solution: I removed the pivot shaft with the end plate in place. I'm just really curious if someone here knows why Yamaha says to remove that plate when it doesn't seem necessary to do so.
The one time I did it, I left it in place. Makes as much sense as having to remove the whole exhaust to get the one bolt out of the suspension linkage that should have been installed from the right side at the factory.
 

RCinNC

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I've never had to remove the whole exhaust system. I did have to remove the exhaust mounting bolt on the right rear side of the bike and loosen the bolts at the exhaust pipe heads. That gave me enough clearance to get the bolt out. I do agree that it was an odd choice for Yamaha to make. I can't see any design reason why they install that bolt that way, and it seems like there'd be no issue just flipping it around at the factory.

I know that happens a lot with vehicles, and with modern vehicle design, it can result in a lot of compromises as far as easy access to and removal of parts (it's amazingly labor intensive to change the spark plugs in a V6 Camry, for instance). In the case of the pivot shaft end plate, I just can't come up with even a dumb reason why they say the plate must be removed.
 

RCinNC

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There is no need to remove the plate to service the swingarm.
I know. That's my point, that it doesn't seem to be necessary, yet the service manual says that you have to. I was hoping someone out there might know why Yamaha says that, in case I'm missing something.
 

Jlq1969

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Argentina
I've never had to remove the whole exhaust system. I did have to remove the exhaust mounting bolt on the right rear side of the bike and loosen the bolts at the exhaust pipe heads. That gave me enough clearance to get the bolt out. I do agree that it was an odd choice for Yamaha to make. I can't see any design reason why they install that bolt that way, and it seems like there'd be no issue just flipping it around at the factory.

I know that happens a lot with vehicles, and with modern vehicle design, it can result in a lot of compromises as far as easy access to and removal of parts (it's amazingly labor intensive to change the spark plugs in a V6 Camry, for instance). In the case of the pivot shaft end plate, I just can't come up with even a dumb reason why they say the plate must be removed.
What I see with, is that the plate is not aligned perpendicular to the center of the bolt. so it is likely that when the nut is pressed to the recommended torque, the plate will bend (just a little), which would put pressure, not only on the nut (to prevent loosening), but also on the thread of the axle(a little). When removing the nut, the pressure exerted on the plate would be lost, but if it is deformed, it could damage the thread of the bolt, when you try to remove it “by turning it”.
4405C061-B302-4C9B-8521-17750A3E39DB.jpeg
 
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